Things You'll Need
3d finish nails
While installing baseboard, the partial or entire end is sometimes exposed. How you terminate that end demonstrates whether or not your project looks professional. Simply cutting it straight and exposing the end grain may work in certain applications, but this option can look crude next to a nicely trimmed area. End grain takes stain differently than the rest of the trim, not to mention it may look like an abrupt termination. There are times when a straight cut is best, but when needed, you have other options.
Baseboard Thicker Than Adjoining Trim
Cut the baseboard to length with a miter saw.
Set the baseboard in place and use a pencil to mark where the outside of the adjoining trim and the baseboard meet.
Hold the back side of the trim against the miter saw and cut a 22-1/2 degree angle through the line. This will soften the transition from the baseboard to the adjacent trim.
Terminating Baseboard Without Showing End Grain
Cut a 45-degree miter on the end of the baseboard. The long point should be on the face of the baseboard.
Cut a 45-degree filler piece to place on the end. This is done by making a 45-degree cut on the end of a piece of baseboard, changing the saw to 90 degrees and cutting off the angled portion you just made. It is helpful to make a line so you know where to cut. The piece is properly cut when you can slip the piece onto the end of your baseboard to fit tightly against the wall and/or adjoining trim. The benefit of this technique is retaining the complete profile of the baseboard with no end grain.
Apply glue to the end piece and set it in place while you are attaching the baseboard. Thicker baseboard may require a couple of nails to keep it in place. If you must nail it, pre-drill the nail holes or use an 18-gauge or smaller nail gun.
If you are staining the baseboard, it is easier to stain the cut you made before nailing it to the wall.